The invention relates to a circuit arrangement for actuating an air-conditioning system or automatic air conditioner in a vehicle. Here, the air-conditioning system or automatic air conditioner can be switched on or off when the engine is operating. Moreover, the air-conditioning system or automatic air conditioner is switched off if the air-conditioning system or automatic air conditioner is switched on when the engine is operating and the engine is subsequently switched off. Additionally, when the engine of the vehicle is stationary, the air-conditioning system or automatic air conditioner continually possesses a function via which the residual heat of the engine is utilizable.
Presently, vehicles are being increasingly equipped with air-conditioning systems. Such air-conditioning systems have a compressor with which air can be cooled. In an air-conditioning system, the power of the compressor is directly set by the driver of the vehicle or an occupant of the vehicle. Here, it is the interior temperature of the vehicle which is controlled. If the temperature of the interior of the vehicle does not correspond to the expectations of the driver or the occupant, the driver or the occupant will change the power setting of the compressor appropriately.
The interior temperature of the vehicle is thus controlled in a closed-loop manner. Similarly, it is known to continuously control such an air-conditioning system in a closed-loop manner so that the air-conditioning system thus becomes an automatic air conditioner. In such an automatic air conditioner, the driver or the occupant of the vehicle must enter the interior temperature setpoint of the vehicle. Using at least one temperature sensor, the power of the compressor is then set in such a way that the temperature setpoint in the interior of the vehicle is maintained. Additionally, or as an alternative, a temperature is also maintained while taking into account other ambient conditions such as, for example, solar radiation. The driver or occupant of the vehicle can expect this temperature to corresponding to the setpoint temperature while accounting for the ambient condition.
Because of the comparatively large power requirement of the compressor, the operation of such an air-conditioning system or such an automatic air conditioner is permitted only if its power is provided by the engine for the vehicle. The air-conditioning system and/or the automatic air conditioner can therefore basically be switched on and off by the driver of the vehicle or an occupant of the vehicle. Here, it is possible to activate the air conditioning system and/or the automatic air conditioner only if the engine is running.
Moreover, it is also known to equip an air-conditioning system or an automatic air conditioner with a further function with which the residual heat of the engine can be utilized to heat the interior of the vehicle. Here, in a manner comparable to the heat exchanger of a conventional heater of a vehicle, heat is then obtainable from the coolant of the engine. With this function, the residual heat of the engine is utilized when the engine is not operating. In the prior art, the on/off switch of the air-conditioning system or automatic air conditioner and the switch for the residual heat utilization function are different (i.e., separate) switches.
It is an object of the present invention to provide a circuit arrangement for actuating an air-conditioning system or automatic air conditioner in a manner such that its control is simplified and the expenditure (in terms of components) is minimized.
This and other objects and advantages are achieved by the circuit arrangement according to the invention, in which at least one function of the air-conditioning system or automatic air conditioner, which is manually switchable when the engine is operating, is switchable via the same control element utilized to activate and deactivate the function of utilizing the residual heat when the engine is stationary.
Here, in comparison to the prior art, an advantage is achieved by eliminating the use of one control element. Since the air-conditioning system or automatic air conditioner is switched off automatically when the engine is switched off, the control element with which the at least one manually switchable function can be switched on or off when the engine is operating can be used (when the engine is stationary(off)) to switch the function in which the residual heat is utilized. This is because at least one function can be switched only when the engine is operating. On the other hand, the function of utilizing the residual heat can be switched only if the engine is not operating. As a result, via this double assignment of the control element, in comparison to the prior art, it is possible to eliminate the use of one control element.
In an embodiment of the circuit arrangement according to the invention, the at least one function of the air-conditioning system or automatic air conditioner, which is manually switchable when the engine is operating, is the activation and deactivation of the air-conditioning system or automatic air conditioner when the engine is operating.
Via this refined embodiment of the invention, the use is simplified insofar as one control element is provided with which different functions can be switched on or off. This proves advantageous insofar as, in the two cases in which the engine is operating and in which the engine is switched off, this control element has a switching-on and switching-off function, i.e., in the switching on/off of the air-conditioning system or automatic air conditioner, and in the other case the switching on/off of the function where the residual heat of the engine is utilized. Therefore, by virtue of the fact that the control element is not used to set any variables, but rather a switching on/off function is implemented, the device is simple for the user to operate (in terms of the control). This is particularly advantageous in view of the comparatively large number of control elements of an air-conditioning system and an automatic air conditioner.
In another embodiment of the circuit arrangement according to the invention, the control element is a switch. In a switch, haptic feedback (i.e., information learned by touching the switch) of the switched state is easily provided. This enables the user to determine which switched state the switch is in.
In yet another embodiment of the circuit arrangement according to the invention, the control element is a pushbutton switch. The actuation of a pushbutton switch can be input by a controller or microprocessor in a simple manner. This is advantageous insofar as it is in any case necessary to use a controller or microprocessor for the open-loop or closed-loop control of the air-conditioning system or automatic air conditioner. Here, in an advantageous manner, it is possible to feed into the controller or microprocessor the external signals in a particularly simple way when pushbutton switches are used.
In a still further embodiment of the circuit arrangement according to the invention, there is at least one display element with which it is possible to display which of the functions can be switched by the control element. As a result, the operation of the device by the user becomes easier. This is because it is always possible to determine which of the functions can be switched via the control element. For example, in each case a designation of the two switchable functions can be printed onto the control element itself. Assignable to each of these designations is a light-emitting diode. Here, the light-emitting diodes is driven in accordance with the operating state of the engine. As a result, it is always possible to determine which function can be switched. Additionally, it is also possible to provide a corresponding display in a display device. Further, the control circuit arrangement can be implemented via software, hardware or some combination thereof, with reference to the controller or microprocessor.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.